First option is not correct as according to historians Sumer was inhabited between 4500 BC and 4000 BC.
Second option is correct as it is believed that this city was established around in 5400 BC. Because of its significance, the city is today under the protection of UNESCO.
Third option is correct as Gilgamesh is the character whose life has been described in one of the first epics that were ever written. Although written in Akkadian language, it tells a story of a semi-mythical king of Uruk.